Australia is nearly as large as the United States, but most of it is too dry for people to live in. Around the edge of this huge dry part are large sheep and cattle farms. A few of them are as large as the smallest states in America. Often the nearest neighbors are many hundred miles away.
　　The two-way radio is very important to people who live on these great Australian farms. It works much like a telephone. A person can listen to someone else talk and give an answer.
　　When these radios first came into use, the Australian government set up for them in some areas. At a certain time each day, the boys and girls turn on their radios and listen to teachers in cities miles away. Families on the large farms wanted to give news to their neighbors. "Round Robin (知更鸟) Talks" by radio were started to keep families in touch with each other. They could talk about who was going away or who was sick or who was getting married. The man could talk about their sheep and cattle and how much money the markets would pay for them. In many ways the radio became a newspaper for the farm people of Australia.
 68.This passage tells us something about 　　.
　　how large Australia is　
　　why the radio is important in Australia　
　　how the radio is used in Australia　
　　both B and C　

 69.The two-way radio is something like a telephone because 　　.
　　the boys and girls can listen to somebody by radio　
　　the radio has two telephones　
　　you can talk to and listen to somebody by radio　
　　people can talk to a doctor hundreds of miles away by radio　

 70.Families on the large farms kept in touch with each other by 　　.
　　radio　 　　　　　a newspaper　 　　a bird　　　　　　both B and C　　　

 71.Which of the following is true?
　　The people on the farms don't have neighbors because they live far away from each other.　
　　Most of Australia is too dry for people to live in and it is the same with the U. S. A...　
　　Some of the Australian farms are very large.　
　　The Australian children don't like to go to school at all.